Fluid-controlling mechanism



Jan. 22, 1929.

' E. S; RUSH FLUID CONTROLLING MECHANISM Filed NOV. 19. 1920 gqwllllllllllllll M avwwmtoz lt atented ten. 22, 1929.

rice.

MEL B. RUSH, OF ZBARTLESVILLE, OKLAHOMA, ASSIGNOR, BY MES NEASSIGNMENTS,

TO DOHERTY RESEARCH COMPANY, OF NEW YORK, N. Y.,

DELAWARE.

A CORPORATION OF FIJIUID-GONTBOIJLING MECHANISM.

Application filed November 19, 1920. Serial No. 425,196.

This invention relates to fluid controlling mechanism, and theillustrated embodiment of the invention is particularly intended for usein the distribution of natural or artiflcial gas to limit the quantityof gas which any consumer may take from the supply mains.

It has heretofore been possible for a consumeroft gas to take from thesupply mains an amount of gas dependent only upon the capacity of theservice piping under his control and the pressure of the gas in themains. Distributors of gas, theretore, have had to take into account thepossibility that a number of consumers may simultaneously withdraw fromthe mains amounts of gas greatly in excess of their normal demands. Inorder to cope with such an exigency,it has been the practice to maintainthe gas in the mains, so far as possible, at a pressure which will per-Init withdrawal of gas considerably in excess of the amount normallywithdrawn from them. In the distribution of gas, however, it is foundthat leakage from the mains is greatly accelerated by increase inpressure, 1n consequence of which the maintenance of pressurescalculated to provide for a the exigency above referred to often entailsgreat loss of gas: Moreover, it sometimes happens, for example, due tothe growth of a city, that the normal demand on the supply mains isgreater than that which was contemplated at the time they were laid,with the result that it is impossible, evenat high pressures, to keepsuficient gas in them to supply all consumers adequately when a con-'siderable number of the consumers are withdrawing gas from the mains inexcess of their normal demands. sumers close to the source of supply,where the gas pressure is naturally greatest, may be able to draw asmuch gas from the mains as they may desire, whereas consumers at theother ends of the mains may be unable to obtain enough gas to satisfytheir normal needs.

It is an object of this invention to provide a device which maybeinstalled in each of the lines of service piping of a gas distributingsystem to limit the demand on the line, to

the end that each consumer may be assured of a normal suppl of gas atall times, The maximum allowe flow of gas through the In such an event,conservice lines so controlled is preferably somewhat greater than thenormal demand but is so proportioned to it as to enable suficientpressure to be maintained in the lines so that a normal supply of gasmay always be procured on an of the lines.

It is a we l-known principle governing the conductance of fluids that ifthe flow of a confined fluid is restricted at a point in a fluidconductor, the withdrawal of fluid from the delivery side of the pointof restriction will cause the pressure on that side to become less thanthe pressure on the other side of the point of restriction. Moreover,the extent of the pressure differential of a fluid on opposite sides ofa point of restricted flow bears a definite relation to the rapidity ofwithdrawal of the fluid; that is, the more rapid the with- .drawal ofthe fluid, the greater is the drop in pressure at the point ofrestriction.

It is a further object of the invention to provide a device in which theprinciple above enunciated may be utilized to limit the quantity offluid which may pass thru the device in any given unit of time,

With these objects in view, an important feature of the inventionresides in the provision of a fluid conductor having associatedtherewith means for causing a drop, in pressure of fluid passing throughthe conductor, and means for controlling the passage of fluidthrough-the conductor in accordance with the pressure difierential ofthe fluid on opposite sides of'the first-mentioned means without regardto the actual pressure of the fluid. In the illustrated construction,the means for causing a drop in pressure of the fluid comprises anorifice disk disposed in the fluid conductor on the outlet side of avalve casing, and the flow of fluid through the valve casing iscontrolled by a valve actuated by,a diaphragm located outside of themain path of flow of fluid through the conductor the pressure of thefluid on opposite sides of the orifice disk being transmitted toopposite sides of the diaphragm.

The above and other features are illustrated in the accompanyingdrawings, in which: I a a Fig. 1 is a view in-plan of a demand limitingdevice embodying the preferred principle of the invention; and

Fig. 2 is a view in elevation of the device taken along the line 22 ofFig. 1 and looking in the direction of the arrows.

The illustrated device comprises a fluid conductor adapted for use inconnection with a domestic gas meter and including a valve casing 2 andinlet andoutlet pipes 4 and 6 respectively. i

As shown, the means for causing a drop in pressure of gas passing.through the conductor comprises a short pipe 8 screwed into the outletside of the valve casing 2 and a union composed of sections 10 and 12held together by a flanged unit 14 and having clamped between them adisk 16 provided with an orifice 18. The sections 10 and 12 of the unionare threaded exteriorly on the pipe 8 and the outlet pipe 6respectively. It is apparent that with this construction, the nut 14 maybe screwed off to the left as seen in Fig. 2 and v the members 8 and 10turned slightly away from the member 12, thus enabling the orifice disk16 to be readily removed and another disk substituted therefor.

The valve casin 2 is divided by a wall 20 into an inlet 0 amber 22 andan outlet chamber 24, andconnecting the chambers 22 and 24 is a port 26.The flow of gas thru I the port 26 is controllel by a valve 28 carriedon'the lower end of a valve stem 30. Accessmay be had to the chamber 24and valve 28 by removing a screw plug 31 at the bottom of the valvecasing 2. Mounted on the valve casing 2 is a second casing 32 comprisingoppositely disposed meniscus-shaped sections 33 and 84 secured togetherat their peripheries by bolts 35. Clamped between the sections 33 and 34is a diaphra 36 carrying an incubus plate 38 and a diaphragm stop "40connected to each other and to the diaphragm 36 by a screw 42. The stop40 is formed with a reduced portion 44 extending thru an opening in thelower section 34 of the dia hragm casing 32 into the valve casing 2 were it is joined to the upper end of the valve stem 30. The passage 0gas from the inlet chamber 22 of the valve casing to the diaphragmcasing 32 is prevented by a diaphragm 46 surrounding the stop 40 andhaving an area such that the pressure of the gas in the chamber 22 onthe diaphragm substantially balances the pressure on the upper surfaceof the valve 28.

To the end that the valve 28 may control the flow of s through the port26 in accordance with t e pressure differential on opposite sides of theorifice disk 16, a port 48 is provided in the outlet chamber 24 of thevalve casing 2 and the lower section 34 of the di aphragm casing 32 toenable the pressure in the chamber 24 to be imparted to the under sideof the diaphra m 36, and a pipe 50 is tapped into the outliat pipe 6 andthe upper section 33 of the casing 32 to transmit the pressure of thegas in the outlet pipe 6 to the upper side of the diaphragm 36.

The manner of operation of the illustrated device-will now be described.Assuming that there is no flow of gas through the device, the pressureson opposite sides of the orifice disk 16 and diaphragm 36 will be equal,and

under side of the diaphragm. So lon however, as only a relatively smallflow 0 gas is set up in the outlet ipe 6, the pressures ,on the oppositesides 0 the diaphragm 36 will vary to a relatively small extent only, sothat the weight of the valve 28 and its associatedparts will stillmaintain the valve in open position. If, however, gas is withdrawnrapidly from the outlet pi e 6, the pressure on the upper side of thediap ragm 36 will be so reduced that the greater pressure of the gasagainst the under side of the diaphragm will cause it, and,consequently, the valve 28 to be raised. When the valve 28 is raised,the flow of gas from the inlet chamber 22 to the outlet chamber 24 isreduced or discontinued,

with the result that the pressure in the outlet chamber 24 graduallyapproaches that in the outlet pipe 6 until a point is reached where theweight of the valve 28 and its associated parts more thancounter-balances the difierence in pressure on the sides of thediaphragm, At such time, of course, the diaphragm 36 is again depressed,thereby opening the valve and permitting more gas to flow through thevalve casing.

When the maximum allowed quantity of gas is being withdrawn from theoutlet ipe 6, a condition of equilibrium is establis ed in the demandlimitin device wherein the pressure difi'erential o the gas on oppositesides of the diaphragm 36 equals the combined weight of the plate 38,stop 40, valve stem 30 and valve 28. It is apparent, therefore, that ifthe combined weight of the above-mentioned parts is increased a ordecreased, while the size of the orifice 18 remains unchanged, themaximum allowed flow of "as through the device will be increased ordecreased respectively.

Inasmuch as an increased flow of gas may be obtained with a givenpressure differential by increasing the size of the orifice 18 in theorifice disk 16, it is manifest that the maximum allowed flow of gas maybe increased by substituting for the orifice disk 16 a disk having alarger orifice. Conversely, if a disk having an orifice of less size issubstituted for the disk previousl in use, the maximum allowed flow ofgas is ecreased. Accordingly, a convenient method of vary' the maximumallowed flow of gas throug the device is .to substitute orifice diskshaving orifices of dif ferent sizes, without other-wise modifying thedevice.

It will be clear from the foregoing that a supply of gas may always bewithdrawn from the device and that the gascan pass through it in a givenquantity only, such quantity being predetermined by the area of thediaphragm 36, the weight of the valve 28 and associated parts, and thesize of the orifice in the orifice disk.

An important advantage of the device is that the valve-actuatingelement, namely, the diaphragm 36, is located outside of the main pathof flow of the gas through the device so that it is substantiallyunaffected by the dynamic forceof thegas passing through the device andis governed only by the pressure differential of the gas on oppositesides of the orifice disk .16. Consequently, the device does not haveto. be calibrated for differences in the actual pressure of gas in themains, and devices of like standard construction may be used in gasdistributing systems or portions of the same system Where the actualpressure of the gasvaries.

Anotheradvantage of the device is that orifice disks having orifices ofdifferent sizes may be used without modifying the effective area of thediaphragm 36. Consequently, the capacity of the device maybe changedwithout affecting the pressure differential necessary to cause the valveto be actuated. The fact that the maximum differential across theorifice-diskis thus maintained conthis invention is that the properoperation.

of the diaphragm 36 and valve 28 is not interfered with by the presenceof dirt or other foreign material in the gas, as is likely to occur in a"device in which the valve-actuating member moves bodily in closejuxtaposition to other parts of the device.

The invention having been described, what is desired to be secured byLetters Patent of the United States is:

1. A fluid controlling mechanism comprising a fluid-conductor, anorifice disk for causing a drop inpressureoffluidpassingthrough theconductor, a valve for controlling the passage of fluid through theconductor, a valve actuating element responsive to the pressuredifferential of the fluid on opposite sides of the orifice disk andmovable independently of the orifice disk so that orifice disks havingorifices of greater or less size may be used without aflecting thepressure fluid, a valve for controlling the passage of fluid through theconductor, and means for actuating the valve in accordance with thedifferential pressure of the fluid on opposite sides of the disc.

3. In a fluid controlling mechanism, a fluid conductor comprising avalve casing, a valve in the valve casing, a diaphragm casing connectedto the valve casing; a diaphragm in the diaphragm casing operativelyconnected to the valve, a fluid connection between the valve casing andtheadjacent side of the diaphragm casing on the outlet side of thevalve, an orifice disk in the fluid conductor at the delivery side ofthe valve casing for causing a drop in the pressure of fluid passingthrough the conductor, and a fluid connection between the fluidconductor at the outlet side i of the orifice disk and the side of thediaphragm casing remote from the valve casmg, the construction beingsuch that the pres-' sures of the fluid in the valve casing and thefluid conductor on opposite sides of the orifice disk are'transmitted toopposite sides of the diaphragm so that the valve is actuated inaccordance with the differential betweensuch pressures.

4. A maximum demand fluid regulator, comprising a valve, and means foractuating the valve upon an abnormal increase in flow beyond apredetermined maximum including a restricted orifice through which thefluid flows, a flexible diaphragm operatively connected with the valveand weighted with a removable weight so as to normally maintain thevalve wide open, and passa es from the upper and lower sides of the diapragm to the outlet and inlet sides, respectively, of the.

orifice, substantially as described.

5. A. maximum demand fluid regulator, comprising a valve normally wideopen, means for actuating the valve upon an abnormal increase in flowbeyond a predetermined maximum, including a removable restricted orificenot accessible to the user, and a diahragm subject to the differentialpressure Between the two sides of the orifice, substantially asdescribed.

In testimony whereof I aflix m signature. i

EARL RUSH.

